Nitrogen isotope fractionation during nitrogen transport from ectomycorrhizal fungi, Suillus granulatus, to the host plant, Pinus densiflora

The N-15 natural abundance in Pinus densiflora Sieb, et Zucc. that had been inoculated and not inoculated with ectomycorrhizal fungi (Suillus granulat us (L.:Fr.) O. Kuntze) was compared. The inoculated pine needles showed a l ower delta(15)N value, while the uninoculated ones showed a higher delta(15 )N value. Higher delta(15)N values in the mycelial mat of the ectomycorrhiz al fungi compared to those of the inoculated pine needles were also observe d. These facts indicate that nitrogen isotope fractionation occurred during the nitrogen transport from mycorrhizal fungi to the host plants.